Expand device for proportional escapement typewriters



March 21, 1967 LENNON 3,310,148

EXPAND DEVICE FOR PROPORTIONAL ESCAPEMENT TYPEWRITERS Filed June 26,1964 5 Sheets-Sheet 1 FIG] I RIGHT SIDE KENNETH A. LENNON LEFT SIDE BYAGENT March 21, 1967 K. A. LENNON 3,310,148

EXPAND DEVICE FOR PROPORTIONAL ESGAPEMENT TYPEWRITERS Filed June 26,1964 3 Sheets-Sheet 2 FIGZ RIGHT SIDE March 21, 1967 LENNON 3,310,148

EXPAND DEVICE FOR PROPORTIONAL ESGAPEMENT TYPEWRITERS Filed June 26,1964 3 Sheets-Sheet. 5

United States Patent Ofifice 3,3lll,l48 Patented Mar. 21, 1967 3,310,148EXPAND DEVICE FOR PROPQRTIONAL ESCAPEMENT TYPEWRITERS Kenneth A. Lennon,Lexington, Ky., assiguor to Intemational Business Machines Corporation,New York, N .Y.,

a corporation of New York Filed June 26, 1964, Ser. No. 378,301 1 Claim.(Cl. 197-84) This invention relates to spacing devices for use withproportional escapement typewriters and in particular to devices of thisgeneral type which provide variable amounts of spacing between the typedcharacters.

Currently, the spacing means with which most proportional escapementtypewriters are provided are of two general types. The first typecomprises one or more spacing keys, or spacebars as they' are frequentlytermed. The spacebars are located on the keyboard and, when actuated bythe typist, produce specified different units of carriage escapement orspacing between the characters. The number of spacebars and the amountof carriage escapement obtainable by depressing a particular one of thespacebars can vary depending on the construction of the particulartypewriter. While such variation in spacing and number of spacebars ispossible, by far the greatest number of typewriters in use are providedwith only two space-bars which produce 2 units of space and 3 units ofspace, respectively. An example of such a machine is the IBM ExecutiveTypewriter, Model C-4.

Summarizing, the first type of character spacing means widely used inproportional escapement typewriters comprises a pair of spacebarslocated on the keyboard. The depression of the spacebars produces either2 units or 3 units of space depending on the particular spacebarsdepressed.

The second type of spacing means common to most types of proportionalescapement typewriters is the keyboard expand feature. This feature,often manifested by a bistable depressable lever mounted on thekeyboard, permits the automatic insertion of an extra unit of spaceafter each printed character and after each spacebar spacing operation.For example, when the keyboard expand feature is utilized, depression ofthe letter key designated will produce a 4 unit carriage escapement ofthe usual 3 unit escapement characteristic of the latter 0, an extraunit of spacing having been automatically added. The same expandedaction results from depression of a spacebar, e.g., depression of the 3unit spacebar produces a 4 unit carriage escapement.

Summarizing, the second spacing feature common to most proportionalescapement typewriters is the keyboard expand means which automaticallyadds an extra unit of escapement to all carriage escapements whetherthey be due to the printing of a character or the depression of one ofthe two spacebars.

While the provision of the two previously noted spacing means, thespacebar spacing and keyboard expand features, has in general been ofaid to the typist, substantial deficiencies still exist in the prior arttypewriter. For example, often the typist finds it necessary to maintainthe normal character spacing, that is, to type without adding an extraunit of spacing between characters, but desires that the spacing beexpanded between the words. Stated differently, the typist desires theuse of the keyboard expand feature only while spacing using thespacebar, but desires normal, unexpanded spacing between printedcharacters. Most frequently, this type of operation is encountered instatistical typing. Here the typist who is typing vertical columns ofnumbers, desires that there be normal spacing between the digitscomprising the numbers, but that the spacing between numbers, which inactuality is the intercolumn spacing, be expanded. Another applicationwhere expanded spacebar spacing, but normal character spacing, isdesired is in the preparation of material for subsequent printingwherein it is necessary that the right hand margins be blocked.

This type of operation, i.e., expanded spacebar spacing, while possiblewith the present spacing features found on conventional typewriters, canonly be achieved with some inconvenience and loss of typing speed.Specifically, if the typist desires normal spacing for the characters,but expanded spacing for the spacebar operations, it would necessitatethe actuation of the keyboard expand feature each time expanded spacebarspacing is desired, i.e., when the spacebar is actuated, and deactuationof the keyboard feature each time normal character spacing is desired,i.e., when the character keylevers are actuated. This constant actuationand deactuation of the keyboard expand feature is extremely timeconsuming. To leave the keyboard expand feature actuated for both thespacebar spacing and the character printing operations, while moreconvenient than periodically actuating and deactuating it, would resultin added units of space being added to all operations and this isexactly what is not desired in a great many instances. Thus, it isreadily apparent that when expanded spacing is desired, only for thespacebar spacing operations, it would be grossly wasteful from astandpoint of typing speed to have to actuate the keyboard expandfeature each time it is desired to use the spacebar.

Summarizing, the proportional escapement typewriters of today aregenerally provided with two spacing means: (a) space-bars which providedifferent degrees of carriage escapement when depressed, and (b)key-board expand means which, when actuated, automatically insert anextra unit of space into all carriage escapements. Collectively, thesetwo spacing features, while being capable of handling many of thecommonly desired spacing operations, fail to conveniently provide forthe situation where it is desired to expand only the spacebar spacingwhile leaving the spacing between characters unaffected.

It is therefore an object of this invention to provide an improvedspacebar spacing mechanism for a proportional escapement typewriterwhich overcomes the above-mentioned shortcomings of the prior art.

It is another object of this invention to provide a new and usefulspacebar space expand mechanism for a proportional escapement typewriterwhich once set permits expanded spacing for spacebar operations andnormal spacing for character printing operations.

It is yet another object of this invention to provide a simple, compact,and durable spacebar space expand mechanism for a proportionalescapement typewriter.

It is still another object of this invention to provide a spacebar spaceexpand mechanism in a proportional escapement typewriter which isindependent of, compatible with, and supplements the existing spacingand expanding functions.

A still further object of this invention is the provision of aproportional escapement typewriter with a spacebar '3 space expandmechanism which does not alter or modify the operation of theconventional keyboard expand and spacebar spacing mechanisms.

A still further object of this invention is the provision of a spacebarspace expand mechanism which does not directly actuate the escapementmechanism.

Therefore, in accordance with one aspect of this invention, I provide anovel combination comprising a bail actuating means and an expandingmeans, which permit selective expansion of the spacebar spacing whenused in conjunction with a conventional proportional escapementtypewriter having a variable escapement mechanism; a plurality ofmoveable bails mechanically linked to the escapement mechanism forproducing varying degrees of escapement when motion is imparted to them;and a first, second and third keylever mechanism. The bail actuatingmeans, which are connected between the bails and the first and secondkeylever mechanisms, respond to the actuation of at least one of thefirst or second keylever mechanisms to selectively impart motion to atleast one of the bails thereby producing a specified escapement of thecarriage. The expanding means, which are connected to the bail actuatingmeans and the third keylever mechanism, are responsive to the actuationof the third keylever mechanism to alter the escapement normallyproduced when the bails are actuated by the first and second keylevermechanisms.

In accordance with a further aspect of this invention, I provide a firstand a second bail which are mechanically linked to the escapementmechanism of a proportional escapement typewriter and which, whenactuated, produce specified different amounts of carriage escapement.Keyboard means including a first, a second, and an expand keylevermechanism connected to the bails via a motion converting means arefurther provided to actuate the bails. Specifically, actuation of thesecond keylever mechanism or the combined actuation of the first andexpand keylever mechanisms is converted to motion of the first bail; andthe combined actuation of the second and expand keylever mechanisms isconverted to motion of the second bail.

In accordance with a still further aspect of this invention, I providethe novel combination of an expand means and an expand keylevermechanism which permit selective expansion of spacebar spacing when usedin conjunction with a proportional escapement typewriter having avariable escapement mechanism and first and second bails mechanicallylinked thereto for producing specified different degrees of escapement;a driving element mounted for limited movement in response to theactuation of a first or second keylever mechanism connected thereto;and, a first element disposed in motion imparting relationship to thefirst bail and which receives its motion from the driving element foractuating the first bail in response to the second keylever. The expandmeans includes a bail actuating means which is disposed inmotion-imparting relationship to the first and second bails and inmotion-receiving relationship with the first element and the drivingelement. The expand keylever mechanism is connected to the expand meansand is operative to effect the movement of the first and second bails inresponse to the combined actuation of the first and expand keylevermechanisms and the second and expand keylever mechanisms, respectively.

In accordance with yet another aspect of this invention, I provide anovel combination of elements and means for selectively actuating thebails of a proportional escapement typewriter having first and secondkeys and having first and second bails mechanically linked to a variableescapement mechanism for producing different degrees of carriageescapement. The novel combination comprises a first element having firstand second motionimparting extensions thereon. This element ismechanically linked to the keys and movable in response to the actuationthereof. The second element of the combination is disposed inmotion-imparting relationship with the first bail and has a thirdmotion-imparting extension thereon. In addition to the first and secondelements, the combination also includes means linked to the second keywhich is selectively interposable between the second and thirdextensions in response to the actuation of the second key. Thisinterposable means transmits motion between the second and thirdextensions thereby imparting motion to the second element and the firstbail. Also provided are third and fourth elements disposed inmotion-imparting relationship with the first and second bails,respectively, and having fourth and fifth motionreceiving extensions,respectively. An expand means mechanically linked with the third andfourth elements selectively positions them in motion-receivingrelationship with the first and third motion-imparting extensions,respectively, in response to the combined actuation of the first key andexpand means and the second key and the expand means, respectively, tothereby impart motion to the first and second bails, respectively.

One of the many advantages flowing from this invention is that thespacebar space expand feature can be incorporated into proportionalescapement typewriters equipped with the conventional spacebar andkeyboard expand features without mechanical interference therewith.Another advantage is that the spacebar space expand mechanism is simplyconstructed and does not require the use of parts manufactured toextremely high tolerances. In addition to the above two advantages, afurther advantage of the invention is that it is relatively trouble-freeover extended periods of use and requires an absolute minimum ofmaintenance. Still another advantage is that the typist is provided witha machine having greater flexibility without compromising speed.

The foregoing and other objects, features and advantages of theinvention will be apparent from the following more particulardescription of a preferred embodiment of the invention, as illustratedin the accompanying drawings.

In the drawings wherein like numerals indicate like elements,

FIG. 1 depicts a schematic in perspective as viewed from beneath themachine of the spacebar spacing mechanism found currently on manyproportional escapement typewriters to which may be added the spacebarspace expand mechanism of this invention.

FIG. 2 depicts an exploded view taken from the left side of the machinelooking toward the front, in perspective, of the conventional spacebarmechanism provided with the spacebar space exanding mechanismconstructed in accordance with this invention.

FIGS. 3(a)3(e) depict the 3 unit spacebar space eX-' pand mechanism ofthe invention in various operative positions as viewed from the leftside of the machine.

FIGS. 4(a)4(e) depict the 2 unit spacebar space expand mechanism of theinvention in various operative positions as viewed from the left side ofthe machine.

Prior art.Spacebar spacing feature A thorough understanding of a typicalspacebar mechanism in wide-spread use today is deemed useful as an aidto understanding applicants spacebar space expanding mechanism. Hence,with t iis in mind, a brief explanation of the structure and operationof the prior art spacebar mechanism will presently follow. However, itwill be understood by those skilled in the art that the exemplary priorart spacebar mechanism depicted in FIG. 1 is only one variety ofspacebar mechanisms to which applicants spacebar space exandingmechanism may be added. Therefore, it is understood that applicant doesnot intend to limit the application of his expanding mechanism to useonly with the spacebar mechanism depicted in FIG. 1, but intends that itbe used with other spacebar mechanisms having similar structural andoperational characteristics.

Again referring to FIG. 1, the inputs to the spacing mechanism,comprising a pair of spacebars 2 and 3, are illustrated. The spacebars 2and 3 are mechanically linked, in a manner to be hereinafter described,to a carriage escapement mechanism (not shown) so as to produce 2 and 3units of carriage escapement, respectively, when depressed by thetypist. The 2 unit spacebar 2 is supported by brackets 6 and 8 which arefastened to the bottom surface of the spacebar by conventional screwfasteners. Each of the brackets 6 and 8 is provided with an extensionwhich is adapted to grip an equalizing rod 10. The equalizing rod 10 hasan offset at each end and is adapted to rotate in the typewriter framegenerally indicated as element 12. The right hand bracket 8 supportingthe 2 units spacebar 2, in addition to being connected to the equalizingrod 10, is also connected by suitable screw fasteners to a lever 14. Thelever 14, provided at its one end with a hole, is mounted on thetypewriter frame 12 for pivotal motion about a rod 16. A tension spring18 connected to the lever 14 and a stationary portion of the typewriterframe (not shown) biases the pivotal lever 14 in an upward direction.The spacebar 2, through the bracket 8, is also biased in an upwarddirection by the spring 18. The equalizing rod 10, which, as has alreadybeen noted, is mounted for rotational motion, is biased in the clockwisesense also by the spring 18. The spring 18 acts through the supportingbrackets 6 and 8, which grip the equalizing rod 10, to thereby transferthe biasing motion of the lever 14 to the rod.

Summarizing, the 2 unit spacebar 2 is supported and biased upwardly by apair of brackets 6 and 8. The brackets 6 and 8 are connected to andbiased upwardly by a lever 14, the lever itself being pivotally mountedat its one end and having its other end upwardly biased by the tensionspring 18. The spacebar 2, acting through the brackets 6 and 8, isadapted to rotate the equalizing rod in a counterclockwise sense when itis depressed by the typist.

The other spacebar 3 is a 3 unit spacebar, and like the 2 unit spacebar2, is mechanically linked to a carriage escapement mechanism (notshown). However, actuation of the 3 unit spacebar 3 produces, in amanner to be described hereinafter, 3 units of carriage escapement. The3 unit spacebar 3 is fastened to a transverse lever 20. The transverselever 20 is mounted on the frame for pivotal movement about a rod 22,and when the spacebar 3 is depressed, it pivots. Fastened to thetransverse lever 20 is another lever 24. Lever 24, like lever 14, has atits one end a hole and is pivotally mounted to the typewriter frame 12and adapted for movement about a rod 26. Lever 24, which is normallybiased upwardly by a tension spring 30 attached to the typewriter frame,has an extension 28. When the 3 unit spacebar 3 is depressed overcomingthe tension of the spring 30, both levers 20 and 24 pivot about theirrespective rods 22 and 26 with the result that extension 28 is lowered.Also connected to the lever 24 is an interposer link 34 the purpose ofwhich will be discussed hereinafter. For the meantime, all that isnecessary is knowledge of the fact that when the 3 unit spacebar 3 isdepressed, the interposer link 34 is lowered.

Summarizing, the conventional proportional escapement typewriter isprovided with two spacebars 2 and 3. Depression of the 2 unit spacebar 2causes the rotation of the equalizing rod 10. Depression of the 3 unitspacebar results in the lowering of extension 28 and the interposer link34.

Adapted to respond to the motion of the equalizing rod 10 and theextension 23 is a lever 32. Lever 32, like levers 14 and 24, has a holeat one end and is mounted on the frame 12 for pivotal movement about therod 36. The lever 32, which is upwardly biased by a spring 38, pivotsdownwardly in response to the downward motion of extension 28 andequalizing rod 10 6 caused by depression of the spacebars 3 and 2,respectively. A cam release link 40 is attached to the lever 32 and isurged downwardly each time lever 32 is caused to pivot under the actionof one of the spacebars 2 or 3.

Attached to the lower end of the cam release link 40 is a cammingmechanism generally indicated by the numeral 44. The camming mechanism44 comprises a cam holder 46 which supports a cam 48 on a pin 49. Thecam holder 46 is mounted to a portion of the typewriter frame (notshown). The mounting comprises a rod 42, which passes through a hole inthe cam holder 46, and permits the camming mechanism 44 to pivot aboutthe rod 42 in response to the camming motion, to be described presently,which is initiated by the downward motion of the cam release link 40. Asindicated previously, downward motion of the cam release link 40 occurseach time one of the spacebars 2 or 3 is depressed.

A continuously rotating power roll 52 is mounted transversely of thetypewriter and in close proximity to the cam 48. When one of thespacebars is depressed causing the cam release link 40 to be actuate-d,the element 41 to which the link 40 is connected, pivots about a pin 43supported by the sides of the cam holder 46. The other end of the lever41 pivots out of engagement with the cam 48 permitting the cam, which isbiased by a spring (not shown), to rotate counterclockwise urging thecam lobe into contact with the power roll 52. The power roll then drivesthe cam through an angle of approximately Following this rotation of thecam, the cam once again is out of contact with the power roll 52 and inengagement with the end of the lever 41 which has returned to itsinitial position due to the return of elements 32 and 40. It will beunderstood by those skilled in the art that the means shown forimparting motion to the links 66 and 54 in response to the actuation ofthe spacebars is merely illustrative of one type of a variety of meanswhich could be used and which forms no part of this invention.

Due to the configuration of the cam surface, the cam holder pivots aboutthe rod 42 imparting motion in the direction of the arrow 55 to the link54. Motion is also imparted to a 2 unit escapement link 60. It is thismovement, the frontward movement of the 2 unit escapement link 60 in thedirection of the arrow 61, which causes the proportional escapementmechanism (not shown) to escape 2 units. The link 60, which it will beremembered is operated each time either of the spacebars 2 or 3 isactuated, is mechanically linked to a proportional escapement mechanismin a manner well known in the art to produce a 2 unit carriageescapement.

Summarizing to this point, a pair of spacebars 2 and 3 are provided,which when actuated, cause a lever 32 to pivot about its end impartingdownward motion to a cam release link 41 The downward motion of the link40 causes lever 41 to pivot about pin 43,releasing the spring-biased cam48 and allowing it to engage the power roll 52 which in turn causes thecam holder 46 to rotate about rod 42. This motion is then transmitted toa 2 unit escapement link 60 connected to the carriage escapementmechanism (not shown) which produces a 2 unit carriage escapement in anywell-known manner. The particular carriage escapement mechanism selectedto perform the 2 unit carriage escapement in response to the motion oflink 60 is of no consequence herein and forms no part of this invention.

As noted above, each time a spacebar is depressed, the camming mechanism44 rotates pulling link 60 to cause a 2 unit carriage escapement.However, in addition to this, there is also another important result: anactuating lever generally indicated by the numeral 56 is pivoted about afixed shaft 62. This pivotal motion is due to the movement of the link54 in the direction of the arrow 55 which overcomes the force of thetension spring 58 to swing the actuating lever 56. The actuating leverhas two legs 64 and 66. The first noted leg 64 is connected to the link54 and receives motion therefrom in the manner indicated previously. Thesecond leg 66 is provided with an car 68 at its free end. When thecomposite actuating lever 56 swings under the urging of the link 54 inresponse to the depression of either of the spacebars, ear 68 swings inan arc toward the rear of the machine. However, the motion of the ear 68is only of consequence when the 3 unit spacebar 3 is depressed.

From the previous discussion it Will be remembered that the depressionof either spacebar actuated link 60 producing a 2 unit carriageescapement. Therefore, it is apparent that a 2 unit carriage escapementcan be obtained irrespective of the presence or absence of link 54 andits associated lever 56 because the 2 unit escapement is produced by theaction of link 60 which occurs each time a spacebar is depressed.

But, the production of a 3 unit escapement is obtained in a differentmanner. It was indicated previously that depression of the 3 unitspacebar 3 caused lever 24 to pivot about its end on the rod 26, andthat this pivotal motion urged the interposer link 34 downward. What wasnot indicated, though, was the function of the interposer link 34because it was not necessary for the production of a 2 unit escapementinasmuch at it did not move when only the 2 unit spacebar was depressed.This interposer link 34 has its lower end connected to an interposerlever 70, which in turn is pivotally connected to a bail actuatingelement 72. When the depression of the 3 unit spacebar 3 pivots lever 24lowering link 34, the net result is that interposer lever 7 swingsdownwardly positioning its forward end in the path of ear 68. Now, whenthe ear 68 swings rearwardly, it imparts motion to the interposed lever70. The motion imparted to the lever 70 causes the bail actuating lever72 to swing rearwardly actuating the 3 unit bail 74, which, throughsuitable linkages to be described presently, causes the carriage toescape three units.

The 3 unit bail 74, of course, is simply a horizontal rod transverselydisposed in the typewriter. The rod has its ends offset and mounted in apair of bail plates 76 (only one bail plate shown). Also, mounted in thebail plates are two other bails: a 4 unit bail 78 and a unit bail 80.All three of the bails are mechanically linked to the carriageescapement mechanism (not shown) by three links 82, 84 and 86. Whenactuated, the 3, 4 and 5 unit bails produce 3, 4 and 5 units of carriageescapement, respectively. It will be remembered that a 2 unit escapementis produced without the aid of a bail by actuation of link 60, alsoconnected to the escapement mechanism (not shown). It is to beunderstood that the particular escapement mechanism is not critical andmay, for example, be one similar to that disclosed in U.S. Patent2,905,303 to Palmer et al. and assigned to the assignee of thisapplication.

While only one of the bails, bail 74, is actuated by the spacebarmechanism, those skilled in the art will understand that the other twobails 78 and 80 are provided to produce 4 and 5 unit spacing in responseto the depression of certain of the character keys. Therefore, theirfunction will not be further explained inasmuch as they are notpertinent with respect to the spacebar spacing operations currentlyfound in contemporary typewriter spacing mechanisms like the prior artone illustrated in FIG. 1.

Summarizing, one of the spacing mechanisms that proportional escapementtypewriters of today are provided with, comprises the 2 unit and 3 unitspacebar spacing mechanism depicted in FIG. 1. This mechanism, it wasindicated, provides a 2 unit carriage escapement when either spacebar isdepressed and the 2 unit escapement is produced without actuating abail. Furthermore, it was indicated that regardless of what spacebar wasdepressed, ear 68 swings rearwardly. If the 2 unit spacebar wasdepressed, ear 68 would pass under interposer lever 70 performing nofunction, the 2 unit escapement produced by link 60 resulting. But, ifthe 3 unit spacebar was depressed, car 68 in its rearward swing wouldurge interposed lever 70 rearwardly actuating the 3 unit bail 74 vialever 72 thereby obtaining a 3 unit carriage escapement.

Prior art.Keyb0ard expand feature The other spacing feature that wasnoted earlier as being present on contemporary proportional escapementtypewriters comprises the keyboard expand feature. Since it is felt thatan understanding of this feature is useful as an aid to understandingapplicants spacebar space expanding mechanism, a brief descriptionthereof will follow. This feature it will be remembered, when actuated,functions to insert automatically an extra unit of escapement into everyoperation whether it be a spacing operation or a character printingoperation. The operation of the keyboard expand mechanism need beunderstood only to the extent that it is clear that such a featureoperates directly on the escapement mechanism and not on the bails.Stated differently, the actuation of the bails is in no way changed ormodified when the keyboard expand feature is being utilized. Forexample, depression of the 0 key actuated the 3 unit bail and only thatbail whether or not the keyboard expand feature is used. As just noted,ordinarily, actuating the 3 unit bail produces 3 units of escapement.However, if the keyboard expand feature is being used, actuating the 3unit bail produces 4 units of escapement. Likewise, actuating the 4 and5 unit bails produces 5 and 6 units of escapement, respectively. Theadded unit of space produced by the escapement mechanism in response tothe bails can be accomplished in any number of ways and forms no part ofthis invention. U.S. Patent 2,547,499 to R. D. Dodge discloses one suchway to produce an extra unit of escapement by bypassing the bails andoperating directly on the escapement mechanism. Another method isdisclosed in U.S. Patent 2,905,303 to L. E. Palmer et al. Both of thesepatents are assigned to the assignee of this application.

Preferred cmb0diment.--De2ailed description With an understanding of theoperation of the two conventional spacing features commonly found onproportional escapement typewriters clearly in mind, a description of apreferred embodiment of a spacebar space expand mechanism constructed inaccordance with the applicants invention will follow. Now referring toFIG. 2, an exploded view in perspective of a preferred embodiment of thespacebar space expand mechanism constructed in accordance with theprinciples of this invention is depicted. This figure shows much of thestructure depicted in FIG. 1. Specifically, the prior art 2 unit and 3unit spacebar spacing mechanism depicted in FIG. 1 and described indetail hereinbefore is substantially reproduced in FIG. 2 except for thecamming mechanism 46. Therefore, for the purpose of orientation, theelements common to both FIG. 1 and FIG. 2 will be described first.

Now, referring to FIG. 2, two spacebars 2 and 3 are provided. The 2 unitspacebar 2 is supported by a pair of supporting brackets 6 and 8. Eachof the brackets 6 and 8 grips the equalizing rod 10 so that when thespacebar 2 is depressed, the equalizing rod 10 will rotate. Adapted tobe actuated by the rotating equalizing rod 10 is a lever 32. This lever32, it will be remembered by referring to FIG. 1, is mounted for pivotalmovement about a rod 36. Connected to the lever 32 is a cam release link40, which, when the 2 unit spacebar 2 is depressed, actuates the cammingmechanism 44 causing the cam 48 to engage the power roll 52. Thisengagement actuates links 60 and 54 in the direction of the arrows 61and 55, respectively. Link 60 produces the 2 unit escapement, while link54, shown also in FIG. 2, is pulled in the direction of the arrow 55.Referring to FIG. 2 it is seen that link 54, which is actuated everytime one of the spacebars 2 or 3 is depressed, is connected to theactuating lever generally indicated by the numeral 56. The actuatinglever 56 has the upper end of its one leg 66 mounted for pivotalmovement about-the shaft 62. An ear 68 forming a part of the leg 66extends sidewardly and swings rearwardly each time lever 56 is swungabout the shaft 62 in response to the actuation of a spacebar. If onlythe 2 unit spacebar 2 has been depressed, the ear 68 will pass beneaththe interposer lever 70 and will perform no function, the 2 unitescapement caused by the motion of the link 60 resulting.

Referring again to FIG. 2, it will be observed that the motion of the 3unit spacebar 3 is transmitted to lever 32 to produce a 2 unitescapement and to actuate link 54 in a manner described in detailhereinbefore. The down ward motion of the 3 unit spacebar 3 is alsotransmitted to the link 34 to position the interposer lever 70 in motionreceiving relationship with .the ear 68 of the lever 56. The interposerlever 70 is connected to the lever 72 and adapted for pivotal movementwith respect thereto.

The lever 72 is mounted for pivotal movement at its upper end about theshaft 62. The lower end of lever 72 is in motion-imparting relationshipwith the 3 unit bail 74. As was seen previously, unless the 3 unitspacebar has been depressed, the interposer lever 70 will not be in itslower position and the rearward swing of ear 68 will not cause the 3unit bail to actuate. However, if the 3 unit spacebar is depressed, therearward swing of the ear 68 will impart motion to the interposer lever70 positioned in its path. The motion of the lever 70 causes the lever72 to pivot actuating the 3 unit bail. Thus, a 3 unit carriageescapement is produced.

Also appearing in FIG. 2 are the other two bails, the 4 unit bail 78 andthe unit bail 80. These two bails, as was described previously, alongwith the 3 unit b-ail 74 have their ends offset and are mounted forrotation in a pair of bail plates 76. Connected to the bails are thelinkages 82, 84 and 86, which are connected to the escapement mechanism(not shown). Actuating the bails 74, 78 and 80 actuates the linkages 82,84 and 86, respectively, thereby producing 3, 4 and 5 units of carriageescapement, respectively. The elements of the preferred embodiment ofthe spacebar space expand mechanism common to the conventional spacebarspacing mechanism having been described, the description of thepreferred embodiment will now focus on the additional elements providingthe expand feature of the invention.

A spacebar space expand lever 90 is mounted on the keyboard and servesto control the expanding function. The lever 90 has two stable positionscalled herein the expand and normal position. The expand control lever90 is mounted onto one end of a support lever generally indicated by thenumeral 92. The expand lever 90 and its associated support 92 aremounted onto the typewriter frame 12 for pivotal movement about a rod94. The rod 94 passes through the frame 12, the forward end of thesupport lever 92, and the expand lever 90. When the expand lever 90 isdepressed, it pivots in a clockwise sense about the rod 94 carrying withit the attached supporting lever 92 which also pivots about the rod.Attached to the midportion of the support lever 92 is a link 96. Thelink 96 is pulled in the direction of the arrow 97 in response to thepivotal motion of the expand lever 90 and the support lever 92. Alsoconnected to the support lever 92 is a coil spring 98 which has itsother end connected to the frame 12. The coil spring 98 is dimensionedsuch that it has 2 stable positions. One of the stable positions is whenthe expand control lever 90 is in the normal, up position and the otheris when it is in the expand, down position. Thus, the combination of thespring 98 and support lever 92 serve to make the expand control leverbistable. Of course, it will be under. stood by those skilled in the artthat other means could be employed for actuating the link 96 and thatthe means described here are only illustrative of one such possibility.

This link 96, which is pulled in the direction of the arrow 97 inresponse to the actuation of the expand control lever 90, is connectedto a four-sided pivoting frame generally indicated by the numeral 100.Two opposing sides 102 and 104 of the frame 100 are mounted for pivotalmovement about the shaft 62. A leftwardly extending extension 106 formsthe front side of the member 100. The rearward side 110 of the member100 is provided with a pair of forwardly extending tabs 112 and 114 thepurpose of which will become evident hereinafter. This four-sided frame100 pivots in a clockwise sense about the shaft 62 on which it ismounted in response to a pull on link 96 caused by actuation of theexpand control lever 90.

Two bail actuating levers 116 and 118 are further provided to furnishthe spacebar space expand function. Lever 116 (FIGS. 2 and 3) has aU-shaped leg 120 extending from its lower portion which embraces the 4unit Ibail 78. The lever 116 has another U-shaped portion 122 whichloosely embraces the shaft 62. In addition to the two U-shapedextensions 120 and 122 of the lever 116, there are two motion-receivingextensions 124 and 126. Extension 124 terminates at the lower surface ofside member 106. A tension spring 128 connected between the tab 112 andthe lever 116 biases the lever 116 upwardly urging the motion receivingextension 124 into I contact with the side member 106 of the pivotingframe 100. Extension 126, also a motion-receiving extension, is on thefront portion of the lever 116 in a position to be described in moredetail hereinafter.

The second of the bail actuating levers, lever 118, has many featuressimilar to those found on the lever 116. Referring to FIGS. 2 and 4, ithas a lower U-shaped extension 130 and an upper U-shaped extension 132.The upper extension 132, like its counterpart 122, loosely embraces theshaft 62. 'The lower U-shaped extension 130, while it too embraces abail like its counterpart 120, it embraces a different bail. Theextension 130 embraces the 3 unit bail 74. The two motion-receivingextensions 136 and 138 are also similar to the extensions 124 and 126,respectively, of the lever 116. Extension 136 contacts the under surfaceof side member 106 as a result of the biasing action of tension spring140 connecting the lever 118 and the tab 114. The other motion-receivingextension of lever 118, extension 138, is positioned on the frontportion of the lever in a position to be described in detailhereinafter.

The last two elements comprising the spacebar space expand mechanism area pair of actuating arms 150 and 152. Referring to FIG. 2, arm 150 formsa portion of lever 56 and moves therewith. At its other end, the arm 150is mounted for pivotal movement about the shaft 62. Carried by the arm150 and located intermediate its ends is a motion-imparting tab 154.When lever 56 swings rearwardly, it also carries with it the arm 150.Hence, the tab 154 on the arm 150 swings in a downwardly and rearwardlyare as the lever 56 pivots under the action of link 54. When the expandcontrol lever is in its normal position the frame is substantiallyhorizontal and the levers 116 and 118 are urged into their uppermostposition by the springs 128 and (FIGS. 3(a) and 4 (a)). Themotion-receiving extension 138 on the lever 118 is located slightlyabove the path of travel of the tab 154 permitting the tab 154 to passbeneath the motion-receiving extension 138 when the lever 56 swingsthrough its arc (FIG. 4(b)). Stated in terms of results, when the expandcontrol lever is in the normal position, tab 154 passes beneathmotion-receiving extension 138 imparting no motion to the lever 118.However, when the expand control lever is depressed, i.e., in the expandposition, the frame 100 has rotated in a clockwise sense about the shaft62 urging the levers 116 and 118 downward (FIG. 3(a) and 4 (0)). Thedownward motion of the lever 118 positions the motion-receivingextension 138 in the path of the tab 154 (FIG. 4(a) Now with 1 l theextension 138 in the path of the tab 154 due to the depression of theexpand control lever 98, the swing of the tab 154 due to the depressionof the 2 unit spacebar 2 imparts motion to the lever 118 actuating the 3unit bail (FIG. 4(d) The other actuating arm 152, referring to FIG. 2,has its one end mounted for pivotal movement about the shaft 62 and itsother end connected to the lever 72 for movement therewith. Intermediatethe ends of the arm 152 is positioned a motion-imparting tab 168. Itwill be remembered that the lever 72 swings in a clockwise sense whenthe 3 unit spacebar 3 is actuated. Hence, the tab 160 on the arm 152will also swing in a clockwise sense when the 3 unit spacebar 3 isactuated. Whether or not the tab 160 imparts motion to its associatedlever 116 depend on whether or not the motionreceiving extension 126 hasbeen positioned in the path of the tab 166. From the previousdiscussion, it will be remembered that the levers 116 and 118 are bothlowered by the action of the pivoting frame 108 (FIGS. 3(0) and 4(0)).Thus, if the expand control lever 90 is in the norma condition, i.e.,the frame 100 has not tilted depressing the levers 116 and 118, the tab160 will pass beneath the extension 126 when the 3 unit spacebar isdepressed imparting no motion to the lever 116 (FIG. 3(b)). However, ifthe expand control lever 90 has been depressed (FIG. 3(0)), theextension 126 is positioned in the path of travel of the tab 166 andeach time the tab 160 swings in response to the 3 unit spacebar 3,motion is imparted to the lever 116 actuating the 4 unit bail (FIG. 3(d)Summarizing, the preferred embodiment of the spacebar space expandmechanism comprises a frame 100, which when tilted in response to theexpand control lever 90, lowers a pair of levers 116 and 118 into thepath of tabs 154 and 168. The tabs impart bail-actuating motion to thelevers thereby expanding the spacing ordinarily obtained when levers 116and 118 are in their uppermost position, i.e., the position obtainedwhen the expand control lever 98 is in its normal position.

Preferred embodiment.-perati0n Normal two unit carriage escapement.-Anormal two unit carriage escapement is produced by the depression of the2 unit spacebar 2, the expand control lever 90 being in its normalposition, i.e., not depressed. Referring to FIG. 1, the depression ofthe 2 unit spacebar 2 rotates the equalizing rod via the brackets 6 and8. The equalizing rod, when rotated, depresse the end of the lever 32which then pivots about the rod 36. The downward swing of the lever 32lowers the cam release link 40 which is attached to the cammingmechanism 44. The downward motion of the cam release link 40 causes thelever 41 to pivot about pin 43 disengaging the cam 48 and allowing it tobe biased into contact with the power roll 52. The cam 48, when itrotates under the action of the power roll 52, pivots the cammingmechanism 46 in a counterclockwise sense about the rod 42. The eiiect ofthi pivoting is twofold: (a) link 54 is pulled in the direction of thearrow 55, and (b) link 68 is pulled in the direction of the arrow 61.The motion of the link 54 is transmitted to the lever 56 through the leg64 swinging the lever 56 in a counterclockwise sense about the shaft 62.However, since the interposer lever 70 is in its uppermost position, itnot having been positioned in the path of the car 68 by the actuation ofthe 3 unit spacebar 3, the ear 68 on the leg 66 swings rearwardlypassing beneath the interposer lever 70 and imparts no motion to it.

The other link actuated by the pivoting camrning mechanism 44, the link60, is mehcanically linked to the escape ment mechanism (not shown) andfunctions to produce a 2 unit carriage escapement. As was discussedpreviously, the particular manner in which the lever 60 produces a 2unit carriage escapement and the particular escapement mechanismutilized can be any of the wellknown types and forms no part of thisinvention.

Thus, depression of the 2 unit spacebar 2 when the expand control leveris in its normal position produces a 2 unit escapement via the link 68and a pivoting of the lever 56, the latter having no efiect since theinterposer lever 70 was not lowered into motion-receiving position bythe action of the 2 unit spacebar 2 and therefore does not move. Duringthe 2 unit spacing operation, neither the bails 74, 78, 80 nor thebail-actuating levers 116, 118, 72 are actuated. This result mustobviously follow if it is realized that the arm 152 carried by the lever72 did not move and, therefore, could not impart motion to the lever 116via the tab 168 to actuate the 4 unit bail '78; and the arm carried bythe lever 56, although it did swing downwardly, can impart nobailactuating motion to the lever 118 via the tab 154 because the expandcontrol lever 98 not having been depressed leaves the lever 118 in itsuppermost position allowing the tab 154 to pass unobstructed beneath themotion-receiving extension 138.

Normal three unit carriage escapement-A normal 3 unit carriageescapement is produced by depressing the 3 unit spacebar 3 while leavingthe expand control lever 90 in the normal (up) condition. Againreferring to FIG. 1, it is seen that depression of the 3 unit spacebar 3causes the lever 20 supporting the spacebar to pivot about the mountingrod 22. When this occurs, the lever 24, which is pivotally mounted onthe rod 26 and also connected to the lever 20, swings downwardlylowering the link 34. The link 34, in lowering, swings the interposerlever 70 into motion-receiving relationship with the car 68.

In addition to positioning the interposer lever 70 in its operativeposition, the pivoting of the lever 28 resulting from depressing the 3unit spacebar 3, also urges the extension 28 downward. The downwardmotion of the extension 28 overcomes the spring 38 to pivot the lever 32about the rod 12. As was described previously with respect to theproduction of the normal 2 unit escapement, when the lever 28 swingsdownwardly, the camming mehcanism 44 is actuated by the link 48 with theresult that the link 68 actuates the escapement mechanism producing a 2unit escapement. Additionally, the link 54 is pulled in the direction ofthe arrow 55 swinging downwardly the lever 56 carrying the car 68.However, unlike the normal 2 unit escapement situation, the interposerlever 70 is positioned in the path of the car 68 and is drivenrearwardly imparting bail-actuating motion to the lever 72 to which itis connected. Thus, the 3 unit bail 74 is actuated. This motion of thebail 74 is transmitted to the escapement mechanism via the link 82. Theescapement mechanism, operating in a wellknown manner, produces a 3 unitcarriage escapement notwithstanding the link 60 was actuated.

Thus, depression of the 3 unit spacebar 3 when the expand control leveris in its normal position causes the lever 70 to be interposed betweenthe swinging car 68 and the 3 unit bail-actuating lever 72 so that theswing of the ear 68 causes actuation of the 3 unit bail 74 by the lever72. As with the normal 2 unit spacing operation motion is neitherimparted to the levers 116 and 118 nor to the 4 unit and 5 unit bails 78and 80 The levers 116 and 118 do not move because they have not beenlowered by the actuation of the expand control lever 90. The tabs and154 pass beneath the motion-receving extensions 126 and 138,respectively, imparting no bail-actuating motion thereto.

Expanded two unit carriage escapement.The expanded 2 unit carriageescapement mode of operation, in actuality a 3 unit escapement, isproduced by the joint actuation of both the expand control lever 90 andthe 2 unit spacebar 2. As was described with respect to the normal 2unit spacing operation, actuation of the 2 unit spacebar causes thelever 56 to swing rearwardly. And, since neither the interposer. lever70 'nor the lever'118 was lowered, the swinging ear.68 and the tab 154imparted no motion to the bail-actuating levers 72 and 118,respectively. However, in the expanded 2 unit spacing mode, thesituation is different: The lever 118 is lowered (FIG. 4(c)) by thetilting action of the frame 100 and the motion-receiving extension 138is now in the path of the tab 154. It will be remembered that actuationof the expand control lever 90 pulls the link 96 causing the frame 100to pivot about the shaft 62 resulting in a lowering of the levers 116and 118 under the action of the front frame member 106. Now, when thelever 56 swings under the action of the link 54, the ear 68 still passesbeneath the interposer lever 71 (FIG. 2) but the tab 154 carried by thearm 150 strikes the motion-receiving extension 138 swinging the lever118 about the shaft 62 (FIG. 4(d)). This swinging motion actuates the 3unit bail 74 producing a 3 unit carriage escapement. Since the lever 72(FIG. 2) has not moved, the arm 152 is not swinging and the tab 160 doesnot strike the motionreceiving extension 126. Therefore, no motion isimparted to the 4 unit bail 78 by the leg 120.

Summarizing, the expanded 2 unit spacing operation produces the samemotions of the elements as produced in the normal 2 unit spacingoperation with one exception: the tilting of the frame 100 by the lever96, which depresses the levers 116 and 118, positions the extension 138in the path of the tab 154 (FIG. 4(c)) thereby imparting bail-actuatingmotion to the lever 118 (FIG. 4(d)). Hence, the 3 unit bail 74 isactuated producing a 3 unit carriage escapement.

Expanded three unit carriage escapement.An expanded 3 unit carriageescapement, in actuality a 4 unit escapement, is produced by depressingthe 3 unit spacebar 3 when the expand control lever 90 is in the expand(down) condition. As was previously described with respect to the normal3 unit carriage escapement operation, actuation of the 3 unit spacebar 3causes both lever 24 and lever 32 to swing downwardly (FIG. 1). Thedownward motion of the lever 24 positions the interposer lever 70 inmotion-receiving relationship with the swinging ear 68 on the lever 56.The downward motion of the lever 32 causes the cam 48 to engage thepower roll 52 thereby producing two additional motions. The link 60which is connected to the escapement mechanism (not shown) is pulledcausing a 2 unit carriage escapement; and the link 54 is pulled causingthe lever 56 to swing (FIG. 2). The swinging motion of the lever 56 istransmitted to the lever 72 via the ear 68 and the interposer lever 70.And, as noted previously, the lever 72, when it moves, actuates the 3unit bail 74.

Referring again to FIG. 2, it will be observed that as levers 56 and 72swing forwardly, the actuating arms 150 and 152, respectively, swingdownwardly. Up to this point, the operation of the normal and expanded 3unit carriage escapements is the same. However, in the normal 3 unitspacing operation, the levers 116 and 118 were in their uppermostposition (FIGS. 3(a) and 4(a)) and hence, when the tabs 160 and 154carried by the arms 152 and 150, respectively, swung downwardly, theypassed beneath the extensions 126 and 138 (FIGS. 3(b) and 4(b))respectively, and no motion was imparted to the levers 116 and 118 norto their associated bails 78 and 74, respectively. Whereas, now, in theexpanded mode of operation the levers 116 and 118 are in their lowermostposition (FIGS. 3(c) and 4(0)) due to the tilting of the frame 100 underthe action of the depressed expand control lever 90 and when the tabs160 and 154 swing they strike the extensions 126 and 138 (FIGS. 3(d) and4(d) respectively, imparting motion to their associated levers actuatingthe bails 74 and 78. Thus, a 4 unit carriage escapement is produced.

Summarizing, the expanded 3 unit spacing operation produces the samemotions of the elements as produced in the normal 3 unit spacingoperation with one exception:

the tilting of theframe by the lever 96, which depresses the levers 116and 118, (FIGS. 3(0) and 4(0)) positions the extensions 126 in the pathof the tab 160 (FIG. 3(d)) thereby imparting bail actuating motion tothe lever 116. Hence, the four unit bail 78 is actuated producing a 4unit carriage escapement. Additionally, the 3 unit bail is actuated.This, however, does not affect the production of a 4 unit escapementanymore than the actuation of the link 60 affected the production of a 3unit escapement. The escapement mechanisms currently used produce anescapement corresponding to the bail actuated having the largest unitvalue.

The preferred embodiment of the spacebar space expand mechanismfunctions equally well regardless of whether lower case or upper caseletters are being typed. When the typist strikes the shift key (notshown) the bail mounting plates 76 rise carrying therewith the bails 74,78, and 80. The bail mounting plates 76 are generally mounted forvertical motion in guides in the typewriter frame provided therefore.Referring to FIGS. 3(e) and 4(a) it is seen that when the bails haverisen in response to the depression of the shift key (not shown), therespective bails 78 and 74 are still embraced by the U-shaped extensionsand 130, respectively. Hence, it is obvious that when the levers 116 and118 are actuated, the associated bails are actuated regardless ofwhether the bails are in their upper or lower position.

While the invention has been particularly shown and described withreference to a preferred embodiment thereof, it will be understood bythose skilled in the art that the foregoing and other changes in formand details may be made therein without departing from the spirit andscope of the invention.

I claim:

In a proportional escapement typewriter, provided with a variableescapement mechanism and having first and second bails mechanicallylinked to said escapement mechanism each operative to produce differentdegrees of escapement, and further provided with first and secondkeylever mechanisms, an auxiliary expand mechanism to contool thespacing effected by said first and second keylever mechanismscomprising:

a first pivotal element having at its free end an extension and a firstactuating arm, said first element being mechanically linked to saidfirst and second keylever mechanisms and pivoting in response to theactuation of said first and second keylever mechanisms;

a second pivotal element having its free end in motionimpartingrelationship to said first bail, said second pivotal element having asecond actuating arm;

interposer means connected to said second pivotal element, saidinterposer means being positionable in motion-receiving relationshipwith said extension in response to the actuation of said second keylevermechanism mechanically linked thereto whereby pivotal motion of saidfirst pivotal element imparts pivotal motion to said second pivotalelement through said interposer means, said pivotal motion of saidsecond pivotal element being effective to impart motion to said firstbail;

a third pivotal element having its free end in motionimpartingrelationship to said first bail;

-a fourth pivotal element having its free end in motionimpartingrelationship to said second bail;

an expand keylever mechanism; and

expand means mechanically linked to said expand keylever mechanism andto said third and fourth pivotal elements and selectively operable bysaid expand keylever mechanism to position said third and fourth pivotalelements in motion-receiving relationship with said first and secondactuating arms, respectively, whereby pivotal motion is imparted to saidthird and fourth pivotal elements by said first and second actuatingarms, respectively, in response to 1 5 the actuation of said firstkeylever mechanism and said expand means, and in response to theactuation of said second keyiever mechanism key and said expand means,respectively, to thereby impart motion to said first and second bails,respectively.

References Cited by the Examiner UNITED STATES PATENTS 2,217,159 10/1940Dodge 19784.1

Dodge 19784.1 Dodge 197-843 Dodge et a1 197-84.1 Palmer et a1 197-84.3Dodge et a1. 19784.3 Roggenstein et a1. 197-84.3

ROBERT E. PULFREY, Primary Examiner.

E. T. WRIGHT, Assistant Examiner.

